With rapid progress of modem technology and the continuous promotion of the human living standard, various kinds of kitchen appliances with multiple functions are applied in our daily lives, and great convenience are brought by such appliances. By applying the multiple functions of such various kitchen appliances, the food can be cooked by different manners, for example as fry\roast\bake\braise\steam\grill\stir-fry, and so on, so the human living standard is being continuously promoted. The present hamburger machine usually equipped with a grill pan, several ribs are parallel arranged on the grill pan, firstly, the ribs can prevent the food on grill pan from easily removed; secondly, the interval between the ribs can equably grill the food. The height of rib of the conventional grill pan is basically similar, when the food is grilled on the rib, the grill degree would not be uniform, for example, the food which leans on the rib would not acquire a good grill degree; further, the rib mark is not obvious, so the food will easily slip on the ribs.